Separable electric socket



May 19, 1936. Y J. A. McKAY 2,041,425

SEPARABLE ELECTRIC SOCKET Filed Feb. 28, 1934 2 Sheets-Sheet l 2? O A;23 22 1M 7@MJ,

2 Sheets-Sheet 2 Filed Feb. 28, 1934 WMJRZM W Patented May 19, 1936UNITED ETATES SEPARABLE ELECTRIC SOCKET John A. McKay, Coshocton, Ohio,assignor to The Jones Metal Products Company, West Lafayette, Ohio, acorporation of Ohio Application February 28, 1934, Serial No. 713,345

10 Claims.

In electric power and light installations in industrial plants andvarious other environments, it is very desirable to employ separablesockets, one portion of which is permanently attached to the electricconductors, enabling a removal of the other portion of the sockets withtheir lamps and reflectors for cleaning, replacement or repair, and alsoenabling the mounting of extra lights in various places or thediscarding of lights already mounted.

Such sockets are frequently used in industrial plants or elsewhere,where it is desirable to have the lights suspended directly over certainmachinery or other objects, and at a height of many feet from the floor.Reflectors, supported on these sockets, are normally quite large and ofconsiderable weight. Two methods are ordinarily used to mount or demountareflector unit with respect to a mating socket. A man may mount aladder and manually hold the reflector while he positions it on thefixed socket. If this means of assembly is used, the sides of thereflector generally preclude the workman from' watching the movement ofthe reflector into the socket.

it is still more difficult for the workman to visually guide the twoparts together if he adopts the method whereby he remains on the groundand retains the reflector portion on a long pole or grapple, by which hereaches the socket to mount the reflector therein.

I-Ieretofore it has been common practice to use a device having the lampmounted within the reflector in a threaded receptacle, which in turn hadprongs extending upwardly to electrically connect the receptacle withthe fixed socket. Due to the practical impossibility of observing theunder face of the fixed socket during the assemblage of the parts,whichever of the two methods outlined above is pursued, the workman isliable to strike the prongs on portions of the fixed socket or a hoodtherefor and bend them in such manner that no effective electricalcontact can be obtained. Particularly is this true when the socket-hoodclosely fits the reflector neck.

An object of my invention has been .to so design a separable unit thatthis injury to projecting parts is avoided. My lamp receptacle hasprongs extending above it, which are adapted to engage contacts in thefixed socket and complete an electrical circuit through the lamp whenthe reflector and socket are fastened together by upward pressure and asubsequent partial rotation of the reflector.

In general, I protect the upstanding prongs by surrounding them by awall some distance outside of the prongs. In mypreferred form, however,I choose to surround the prongs with a cylindrical wall, which issubstantially a continuation of the reflector neck and of the samediameter and rises higher than the prongs. Such a construction allows meto form a cylindrical unit, equal in diameter to the reflector neck andwith one end partially closed. This flat, closed end may rest firmlyagainst a similar portion of the reflector neck and may be suitablyfastened to it. The equality in diameter between the guide and thereflector neck permits a single die to be adapted to form both parts,and further such a construction results in a continuous, cylindricalsurface, which may be easily guided into the socket.

This cylindrical neck portion of the reflector may be designated as amale portion. The mating female portion of the socket embraces thereflector neck and at its lower end flares out to assume a funnel shape.This facilitates the guiding of the reflector into engagement with thesocket, and is of distinct advantage, particularly when the assembly ismade by a workman standing on the floor many feet below the socket. Thisflaring portion serves the additional purpose of acting as a shield forwater if the device is mounted outdoors, or indoors if in a place wherewater may drip down upon it.

Other objects of my invention will become apparent from the followingspecification and the drawings hereunto annexed. These drawings show theinternal portion of the fixed socket and the coacting parts of the lampreceptacle, substantially as shown and claimed in my prior Patent No.1,940,429, issued December 19th, 1933 to my assignee, The Jones MetalProducts Company of West Lafayette, Ohio, though the present inventionis independent of the particular details of such internal parts.

Referring now to the drawings, Fig. 1 is an elevation of a socket with areflector mounted therein; Fig. 2 is an elevation of a socket, withreflector mounted on a grapple and being mounted in the socket; Fig. 3is. an enlarged vertical section through the socket; Fig. 4 is anenlarged vertical section through the base portion of the reflector withthe cylindrical protective guide thereon; Fig. 5 is a section throughthe socket, as indicated by 5-5 in Fig. 3; Fig. 6 is a section throughthe cylindrical guide, as indicated by 5-8 on Fig. 4; Fig. 7 is avertical section through the socket, the cylindrical protecting ring andthe reflector base in assembly; Fig. 8 is a detail in cross-section onthe line 8-8 on Fig. 6 of the fastening member in the lamp receptacle.

As shown in the drawings, the fixed portion of the socket i0 is flrmlyfastened to a pipe II, which, in turn, is fixed in a roof beam or otheroverhead supporting member. The socket I0 has a surrounding shell I3with its lower extremity flared, as at l2, adapted to guide thereflector into the socket. The reflector comprising a comparativelylarge shield |6 terminates in a cylindrical neck I 5, which contains thereceptacle for the lamp l8.

To connect the neck |5 to the socket |0, a suitable grapple may beemployed. This grapple is preferably mounted on a pole of suflicientlength to enable the operator to stand on the floor below the lamp. Sucha device includes suitably operated hooked arms 2|, mounted on a pole22. At the lower end of the pole 22 is suitable means, as a hand crank23, adapted to operate the grapple. Thus, when the reflector has beenmounted in the socket, it is possible to disengage the grapple from theedge of the reflector by moving the arms to carry the notches 24 out ofengagement with the bottom edge of the shield IS.

The flt between the cylindrical shell l3 of the socket III, with theneck l5 of the reflector, should have sufllcient clearance to permit theinsertion of the latter into the former at an angle, as suggested byFig. 2.

Mounted in the neck l5 of the reflector'is the lamp receptacle 25. Forease in assembly, the main portion 25 has a second portion 26 mountedthereon, fashioned of a suitable insulating material. This portion iscup-shaped and has within it the actual support for a lamp. Acylindrical threaded portion 21 of good, electrical conductivity, isadapted to embrace and retain the base of a lamp and furnish one of theelectrical contacts thereto, while a spring member 28 of conductingmaterial is adapted to engage a second electrical contact of the lamp,in a wellknown manner. These two electrical connections to the lamp areconnected in their turn to prongs 30 and 3|, extending upwardly beyondthe neck portion |5. Suitable interlocking means are provided on thefixed socket and the lamp receptacle, so that an upward pressure of thelatter, followed by a. substantially quarter rotation, will effectivelyhold the parts together until released by an upward pressure and thereverse rotation. The means shown will be described later.

To protect the prongs 30 and 3| from bending, the circular guidingmember is mounted about them. This protecting ring comprises a side wall36, terminating in a flat, partially enclosing endportion 31, adapted tobear against the end I! of the neck l5. Although not necessary, it ispreferable that the diameter of the ring 36 be equal to the diameter ofthe neck |5. The ring 35 is shown as fastened to the neck I 5 bysuitable r screws 38, which also support the receptacle 25.

The cylindrical wall 36 of the ring is flanged over at its top, as at39, to eliminate any sharp edges and to render the ring more rigid. Toretain a uniform diameter along the neck and the ring, this flangeportion 39 is formed on the inner side of the ring 35.

As already mentioned, the cylindrical portion of the socket shell l3terminates at its lower end in a flared portion l2. Accordingly, when aworkman isassembling the two parts, he need only locate the ring 35within the confines of an area represented by the larger diameter of theflared portion, upon which he can move the reflector up to complete theassembly. To present a more workmanlike construction, the flared portionl2 terminates in an external bead l9.

To support the socket I have shown a pipe threadingly engaged with amember 40, which supports the parts efl'ecting an electrical connectionwith the reflector. This member 40 has a flange 4| which presents a flatsurface to support the inturned end 42 of the socket shell. A ring 45threadingly engages the member All and clamps down on a washer 43 andthe shell portion 42 interposed between the portion 4? and a cooperatingface of the ring 45.

Electrical contact with the receptacle prongs 3| and 30 is effected bytwo concentric arcuate contact strips and 5| in the socket portion.Suitable lead wires 56 and 51 are removably fastened to the arcuatecontact strips by screws 58, and pass upwardly through the pipe ii tothe source of electrical current. These contacts are so mounted on aninsulated block 52 that each of them will engage a corresponding prongof the receptacle 25, as soon as the latter is pressed upwardly andthroughout its turning movement into locked position. Thus, the prong3|, which protrudes directly upwardly, engages the inner ring 50, whilethe outwardly extended prong 30 engages the outer ring 5|.

It is' thus apparent that it is impossible to mount the receptacle inthe socket in such a manner that electrical current may flow through thelamp in a different direction from that which it took when thereceptacle was formerly mounted in the socket. This maintenance of asingle direction of flow of electric current may be desirable whendirect current is employed and electrical equipment requiring a certaindirection of current is connected to the contacts in the receptacle 25.

I will now describe the locking means to retain the reflector and lampreceptacle firmly in the socket after engagement has taken place. I haveshown for this purpose substantially the mechanism of my prior patent,which is as follows:

A stud is mounted on a stirrup 6|, fastened to the member 40 by screws62. A rectangular head or stop 63 is rigidly formed on the stud 60. Theinsulator block 52 loosely surrounds the stud and is pressed downwardlyby a compression spring 65. I prevent rotation of the insulating block52 by forming a transverse slot 66 in the upper face thereof, thestirrup 6| occupying the slot in all positions of the block. Theinsulating block 25 of the removable portion of the socket carries anupstanding stirrup 10, having a rectangular hole 1|, slightly largerthan the exterior of the head 63. Accordingly, by pressing the removableportion upwardly with the opening H in registration with the head 63,the insulating block 52 may be shoved upwardly, and then the lowerportion turned so that the opening H becomes transverse of the head 63,whereby the stirrup l0 rests on top of the head.

For ease of assemblage, a rectangular hole 61, somewhat larger than thestud head 63 is made through the insulating block 52. Screwed to theunderface of this block is the locking plate 68, having a rectangularhole through it and capable of being clamped to the block in differentpositions, as by the screw 69 passing through arcuate openings in theplate. When the opening of this plate registers with the opening in theblock,

iii

the block is readily passed axially of the stud beyond the head 63; thena partial rotation of the locking plate 58 into the position shown inFig. 5, locks these parts together while allowing the insulating blockto be pressed backwardly from the head 63, against the action of thespring 65.

In the locking rotation of the reflector and lamp receptacle, aninclined downward projeetion 14 (Figs. 6 and 8) on the underface of thestirrup l0 slides over the upper face of the head 63 and then as aquarter rotation is just about completed this projection passes beyondthe head and the spring forces the attached separable portion downwardlyso that the head lies between the abrupt face of the inclined projectionI4 and a longer positive projection 15. This definitely locks the twoparts of the socket together until a slight upward movement is given tothe lower portion suflicient to raise the projection 14 above the upperface of the head 63.

While the locking means and the general characteristlcs of the internalportions of the separable socket described are substantially inaccordance with my prior patent mentioned, the present inventionmaterially improves the socket of that patent in protecting the exposedprojecting contact prongs of the removable member and at the same timeforming an effective guide for the movable portion as it is pushedupwardly within the hood of the stationary portion. With the presentimprovement the insertion of the reflector can be started at quite anangle to the vertical. It makes no diiierence how far out of axialregistration the movable member may be when shoved upwardly, provided itis somewhere within the extreme area of the bell mouth 52 of the hood.Even if the top of the shield abuts the extreme edge of the bell mouth,no harm is done to the contact prongs, and it is only necessary for theoperator to then move the reflector nearer the fixed axis till theextreme edge of the protecting wall is within the bell mouth. Thereplacement of the reflector, accordingly, can be made with ease andrapidity, notwithstanding the distance of the workman when applying it,or the inaccessibility of the space directly below the socket, or thelack of adequate illumination in the vicinity of the socket.

I claim:

1. In combination with a separable socket comprising a fixed part and amovable part, each having a pair of contacts adapted to coact with thoseof the other part, and means surrounding the contacts of the movablepart adapted to slidably guide said movable part into registration withthe fixed part, and other means, in-

dependent of the guiding means, for locking. the

movable part to the fixed part.

2. In a separable socket, the combination of a fixed socket portion, aremovable socket portion, slidable means on one portion to guide theother portion therein, by purely vertical movement, upwardly extendingprongs on said other portion and an embracing protective membersurrounding said prongs, said protective memher being arranged to engagethe fixed socket before the prongs on the movable member may contact anypart of the fixed member.

3. In a separable electric socket, a fixed socket portion, including acylindrical shell flaring outwardly at one end, a removable socketportion, cylindrical in shape, and adapted to nest with said fixedportion, contact prongs extending from said removable portion, and aring of substantially equal diameter with said removable portionembracing the prongs, said ring being of suflicient height to preventcontact of the prongs with any other member before engagement with thehood is made.

4. In a separable socket, the combination of a member adapted to befixed to a support, an insulator carried by said member, a pair of arcuate electric contacts on the underface of said insulator, a dependingsurrounding hood, as a part of said first-named member, and a movablemember comprising a lamp receptacle and a pair of longitudinallyprojecting contact prongs connected therewith, a cylindrical wall rigidwith the movable member and surrounding the pair of prongs some distancebeyond the same and adapted to engage the inner side of the hood andform a guide to bring the prongs into registration with the arcuatecontacts of the insulator, interlocking means independent of the guidingmeans on the fixed member and movable member for causing the same to beattached by an upward and rotating movement of the movable member, and aflaring reflector having a cylindrical neck surrounding the lampreceptacle and rigidly connected with said receptacle and with theprotecting wall.

5. In a separable electric socket, the combination of a fixed socketportion and a removable socket portion adapted to nest therein, means toeffect such nesting by a straight vertical movement of said removableportion, followed by a partial rotation of the same, said removableportion including a lamp receptacle and having prongs extending beyondthe end thereof and adapted to engage said fixed socket portion, saidextended prongs being protected by a ring mounted on said removableportion.

6. The combination of a fixed member having a pair of electric contactsand a surrounding hood, and a movable member adapted to be attached to areflector and lamp receptacle and carrying a pair of contacts extendingbeyond the end thereof and adapted to coact with the contacts of thefixed member and a wall surrounding said contacts on the movable member,and adapted to engage the hood by a non-rotative sliding motion, andmeans to lock the movable member in accurate registration with the fixedmember upon a completion of said non-rotative sliding motion by apartial rotation of the fixed member and the movable member with respectto each other.

'7. In a separable socket, the combination of a fixed portion adapted tobe fastened to a support, and a removable portion adapted to nest withsaid fixed portion, said removable portion comprising a cylindricalshell, flaring at one end and partially closed at the other, an electriclamp receptacle fixedly mounted within the cylindrical shell of saidremovable portion, said receptacle having prongs extending beyond saidpartially closed end together with a protecting ring of substantiallythe same diameter as said shell mounted on said partially closed end andembracing said prongs.

8. In a separable electric socket, a fixed portion and a removableportion, said removable portion comprising a cylindrical shell, flaringat one end and partially closed at the other, a second cylindrical shellequal in diameter with said first shell, open at one end and partiallyclosed at the other, the two partially closed portions of said shellbeing fastened together to form an integral unit, a lamp receptacleretained within the first shell having a pair of contact prongsextending into the region surrounded by said second shell, and meanscarried by the fixed portion and the removable portion but (meetingindependently of both of said cylindrical shells and the removableportion for positively locking the removable portion into the fixedportion.

9. In combination with a separable socket comprising a fixed and amovable part, each having a pair of contacts adapted to coact with thoseof the other part, of means within the socket and carried by-the movablepart and extending beyond the contacts of the movable part adapted toslidably guide said movable part into registration with the fixed partand other means independent of the guiding means for locking the movablepart to the fixed part.

10. The combination of a fixed member having a pair oi arcuate contactsand a surrounding hood depending below the contacts, a movable memberincluding a reflector having an upstanding neck adapted to enter thehood, said neck carrying Within it a lamp receptacle, said movablemember having a pair of contact prongs adapted to contact with thearcuate contacts of the fixed member, said movable member having also awall surrounding the prongs and of substantially the same diameter asthe neck, said wall being adapted to engage the hood to guide themovable member into accurate registration with the fixed member andbeing sufficiently high to prevent contact of the prongs with any othermember before engagement is made with the hood.

JOHN A. McKAY.

